For those wanting to make image larger, do it yourself by altering the .css file in /usr/share/themes/base/meegotouch/libsysuid-screenlock-nokia/style.

There is a header regarding the operator logo along the lines of MImage LowPowerMode Operator Logo. It is the one only with maximum-size, the one with 3 sizes is hidden logo. Alter that to 40mm 40mm and you should be right :)

Works great. One feature I'd like is to be able to convert images from gallery to properly dithered images. Additional option could be to convert to black&white. Also, would it be possible to make the image larger? Similar to sleeping screen on Symbian.